The present invention relates to a file mirroring drive, and more particularly to a file mirroring drive that mirrors data on a file basis.
In general, a disk failure that occurs in a data processor sometimes destroys files and results in a loss of critical data. One way to prevent data from being destroyed is to mirror a disk. That is, all data in a disk is copied to another place. A conventional data processor duplicates data on a disk volume basis to prevent data from being destroyed.
However, on a unit such as a personal computer, the critical files to be duplicated are only apart of all files. Considering the cost, it is not practical to mirror data on a volume basis. Because the minimum unit of mirroring is a disk volume, the whole disk volume must be mirrored at mirroring time even if the user wants only some files to be fault-tolerant.
The object of the present invention is to provide a file access processor which mirrors data on a file basis.
According to one aspect of the present invention, a file access processor, which accesses a storage unit storing a plurality of files therein based on an access request from a request source, is provided which includes: a mirroring relation storage unit in which mirroring relation information is stored, wherein the mirroring relation information includes a mirroring attribute value indicating whether or not each file is to be mirror-accessed and, when the file is to be mirror-accessed, mirroring file information indicating a mirroring file corresponding to the file; and a file access processing unit which references the mirroring relation information based on the access request and accesses the storage unit.